I. noun — [ mass noun] 1. disinterested and selfless concern for the well-being of others. • some may choose to work with vulnerable elderly people out of altruism.
[Zoology] behaviour of an animal that benefits another at its own expense.
• reciprocal altruism.
II. derivatives altruist /ˈaltruːɪst / noun
– origin mid 19th cent.: from French altruisme, from Italian altrui ‘somebody else’, from Latin alteri huic ‘to this other’.